The invention relates to an electronic trip device comprising a case, an electronic processing circuit located inside the case, connection means for connecting the processing circuit to conductors of a power system to be protected, means for determining tripping parameters comprising a removable module, means for fixing the removable module on a front panel of the case, the removable module coming into contact, in the fixed position, with the processing circuit. The use of a removable module for determining long delay protection parameters is conventional in electronic trip devices. Some trip devices comprise a processing circuit directly connected to conductors of a power system to be protected, so as to enable voltage measurement, for example by means of a resistive dividing bridge. This direct connection, without a transformer, must be able to be interrupted, in particular to carry out dielectric isolation tests. In certain protection apparatuses a removable device is provided located on the front panel which, when it is removed, interrupts the voltage connection.